电机线棒环氧云母绝缘老化特性研究  

Study on Ageing Characteristics of Epoxy-mica Insulation for Generator Bar

作　　者：戈宝军[1] 黄启昭 陶大军[1] 刘骥[1] GE Baojun;HUANG Qizhao;TAO Dajun;LIU Ji(National Engineering Research Center of Large Electric Machines and Heat Transfer Technology,Harbin University of Science and Technology,Harbin 150080,China)

机构地区：[1]哈尔滨理工大学大型电机电气与传热技术国家地方联合工程研究中心,黑龙江哈尔滨150080

出　　处：《绝缘材料》2021年第7期53-58,共6页Insulating Materials

基　　金：国家自然科学基金资助项目(51907042)。

摘　　要：为将频域介电谱测试技术应用于大型电机定子线棒绝缘老化状态的无损检测中,在热、电、机械等多因子联合作用下对定子线棒环氧云母绝缘进行加速老化试验,测试不同老化程度试样的频域介电谱。采用最小二乘法提取频域介电响应的Davidson-Cole模型参数作为特征参量,采用特征参量分析环氧云母绝缘的老化程度。最后通过拟合建立特征参量与老化时间的关系。结果表明:环氧云母绝缘的介质损耗因数tanδ随老化程度的增加而增大,尤其在频率为10^(-3)~10^(-1)Hz有明显的增大趋势;Davidson-Cole模型提取的特征参量β和τ可用于表征绝缘的老化程度,β随老化时间的增加线性减小,τ随老化时间的增加呈指数函数减小,Δε随老化时间的增加明显增大。通过τ与老化时间的拟合关系,得出了定量表征绝缘老化程度的公式,可以考虑作为老化程度评估的经验公式。In order to apply the frequency domain spectroscopy test technology to nondestructively test of ageing state for large electric machine stator bar insulation,we conducted accelerated ageing tests on the epoxy-mica insulation of stator bar under the combined action of multiple factors such as heat,electricity,and machinery,and tested the frequency domain spectroscopy of samples with different ageing degrees.The Davidson-Cole model parameters of frequency domain dielectric response were extracted as characteristic parameters by least square method,and the ageing degree of epoxy-mica insulation was analyzed according to the parameters.Finally,the relationship between characteristic parameters and ageing time was established by fitting.The results show that the dielectric loss factor(tanδ)of epoxy-mica insulation increases with the increase of ageing degree,especially at the frequency of 10^(-3)-10^(-1) Hz;the characteristic parametersβandτextracted by the Davidson-Cole model can be used to characterize the ageing degree of insulation.With the increase of ageing time,βdecreases linearly,τdecreases exponentially,whileΔεincreases obviously.A formula for quantitatively characterizing the degree of insulation ageing is obtained through the fitting relationship betweenτand ageing time,which can be considered as an empirical formula for evaluating the ageing degree.

关 键 词：大型电机 频域介电谱 环氧云母绝缘 Davidson-Cole模型 

分 类 号：TM215[一般工业技术—材料科学与工程]